package com.wltt.healing.healingusercommon.utils;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.springframework.util.Base64Utils;

import javax.crypto.*;
import java.io.UnsupportedEncodingException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;

/**
 * @Author: wltt
 * @Date: 2021/9/8 15:26：
 * @Version: 1.0
 * @Description: TODO
 */
public abstract class AESUtil {

    private static final Logger logger = LogManager.getLogger(AESUtil.class);

    private static final String KEY_ALGORITHM = "AES";
    private static final String DEFAULT_CIPHER_ALGORITHM = "AES/ECB/PKCS5Padding";//默认的加密算法

    /**
     * AES 加密操作
     *
     * @param content 待加密内容
     * @param key     加密密钥
     * @return 返回Base64转码后的加密数据
     */
    public static String encrypt(String content, String key)
            throws NoSuchPaddingException, NoSuchAlgorithmException,
            UnsupportedEncodingException, BadPaddingException,
            IllegalBlockSizeException, InvalidKeyException {
        Cipher cipher = Cipher.getInstance(DEFAULT_CIPHER_ALGORITHM);// 创建密码器
        byte[] byteContent = content.getBytes("utf-8");
        cipher.init(Cipher.ENCRYPT_MODE, getSecretKey(key));// 初始化为加密模式的密码器
        byte[] result = cipher.doFinal(byteContent);// 加密
        return Base64Utils.encodeToString(result);//通过Base64转码返回
    }

    /**
     * AES 解密操作
     *
     * @param content
     * @param key
     * @return
     */
    public static String decrypt(String content, String key)
            throws NoSuchPaddingException, NoSuchAlgorithmException,
            InvalidKeyException, BadPaddingException,
            IllegalBlockSizeException, UnsupportedEncodingException {
        Cipher cipher = Cipher.getInstance(DEFAULT_CIPHER_ALGORITHM);
        cipher.init(Cipher.DECRYPT_MODE, getSecretKey(key));
        byte[] result = cipher.doFinal(Base64Utils.decodeFromString(content));
        return new String(result, "utf-8");
    }

    /**
     * 生成加密秘钥
     *
     * @return
     */
    private static SecretKey getSecretKey(final String key) throws NoSuchAlgorithmException {
        KeyGenerator keyGenerator = KeyGenerator.getInstance(KEY_ALGORITHM);
        SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG");
        secureRandom.setSeed(key.getBytes());
        keyGenerator.init(128, secureRandom);
        return keyGenerator.generateKey();
    }

    public static void main(String[] args) throws Exception {
        String content = "aaaa";
        String key = "123456";
        System.out.println("待加密字符串: " + content);
        String s1 = AESUtil.encrypt(content, key);
        System.out.println("密文: " + s1);
        System.out.println("明文: " + AESUtil.decrypt(s1, key));

    }
}
